In recent years it has been pointed out that certain kinds of halogenated hydrocarbon compounds used in cleaning applications may adversely affect the stratospheric ozone layer when released into the atmosphere. Although this proposition has not yet been completely established, there is a movement toward the control of the use and the production of certain chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC)-based cleaning compositions under an international agreement. Accordingly, there is a demand for the development of new compositions that have a lower ozone depletion potential than conventional CFC and HCFC-based cleaning compositions, while still achieving acceptable utility in cleaning applications.
In refrigeration and cleaning apparatus, compositions may be lost during operation through leaks in shaft seals, hose connections, soldered joints and broken lines. In addition, the working composition may be released to the atmosphere during maintenance procedures on equipment. If the composition is not a pure component or an azeotropic or azeotrope-like composition, the composition may change when leaked or discharged to the atmosphere from the equipment, which may cause the composition remaining in the equipment to become flammable or to exhibit unacceptable performance. Accordingly, it is desirable to use as a refrigerant or cleaning composition a single fluorinated hydrocarbon or an azeotropic or azeotrope-like composition which fractionates to a negilgible degree upon leak or boil off.
Hydrofluorocarbons (HFCs) have been proposed as replacements for CFCs and HCFCs in cleaning and drying compositions used by the electronics industry. However, many HFCs have limited solvency for electronics industry soils such as hydrocarbon or silicon oils and soldering flux residues. Accordingly, there is a need for HFC-based cleaning compositions which exhibit acceptable solubility for such electronics industry soils.
In applications where the potential of fire and fire's toxic byproducts are a concern, it is desirable for refrigerant and cleaning compositions to be nonflammable in both liquid and vapor phases, during operation and when charging fresh composition to a system or after composition has leaked from a system. Accordingly, it is preferred that compositions used to replace the conventional HCFC and CFC-based compositions are nonflammable.
It is also desireable that compositions offered to solve the aforementioned problems have a low global warming potential (GWP).
For the foregoing reasons, there is a need in the electronics industry, and industries supporting those requiring cleaning solutions, as well as the refrigeration industry, for compositions that solve the aforementioned problems.